Stroke: Vascular and Interventional Neurology Stroke Vasc Interv Neurol. 2026;6:e002170. DOI: 10.1161/SVIN.125.002170 May 2026 

ORIGINAL RESEARCH Prehospital Detection of Large Vessel Occlusion and Intracerebral Hemorrhage Using a Dual-Biomarker Point-of-Care Test Arnab Ghosh, BSc*; Noah L.A. Nawabi, BS*; Diana Alcedo, MS; Rodolfo E. Alcedo Guardia , MD; Juan Vicenty-Padilla , MD; Saef Izzy , MD; Nirav J. Patel , MD; Rose Du , MD, PhD; Adam A. Dmytriw , MD; Alfred P. See , MD; Mohammed Ali Aziz-Sultan , MD, MBA; Toby I. Gropen, MD; David Liebeskind , MD; Erickson F. Torio , MD; Anil Can, MD; Lennard Spanehl , MD; Edoardo Gaude , PhD†; Joshua D. Bernstock , MD, PhD, MPH†

BACKGROUND: Timely identification of stroke subtype is critical for triage and treatment. Existing prehospital stroke scales have limited diagnostic accuracy, especially in differentiating large vessel occlusion (LVO) from intracerebral hemorrhage (ICH). The LVOne point-of-care test measures d-dimer and GFAP (glial fibrillary acidic protein), biomarkers associated with thrombotic and hemorrhagic stroke, enabling biologically informed triage.

METHODS: We validated a new version of the LVOne assay using plasma samples from 210 suspected stroke patients presenting within 6 hours of symptom onset, enrolled in the TIME (Testing of Identification Markers for Stroke) prospective observational cohort. This article reports a retrospective (secondary) laboratory analysis of these prospectively collected samples and clinical data. Samples were collected before neuroimaging or thrombolysis. LVOne version 1 combined d-dimer positivity, GFAP negativity, and Field Assessment Stroke Triage for Emergency Destination scoring for LVO detection only; version 2 uses improved GFAP measurement and a clinical decision rule enabling simultaneous diagnosis of LVO and ICH. Diagnostic performance (sensitivity, specificity, positive predictive value, negative predictive value) was calculated for each version. Receiver operating characteristic analyses and biomarker correlations with Field Assessment Stroke Triage for Emergency Destination were also performed.

RESULTS: Both LVOne versions achieved high accuracy for LVO detection (sensitivity, 0.75; specificity, 0.92; negative predictive value, 0.97). Version 2 improved ICH specificity (0.99 versus 0.90) and positive predictive value (0.83 versus 0.23) versus version 1. Biomarker levels correlated with Field Assessment Stroke Triage for Emergency Destination scores but with limited explanatory power (GFAP R2=0.077; d-dimer R2=0.047), suggesting added information beyond clinical severity scales. In a specimen-matrix comparison (n=25), qualitative GFAP/d-dimer classification was concordant across plasma, venous whole blood, and capillary whole blood.

CONCLUSIONS: The updated LVOne assay enables simultaneous biomarker-based identification of both LVO and ICH in suspected stroke patients. Its rapid, low-complexity format supports prehospital use and may improve triage, reduce time to treatment, and optimize outcomes. Prospective field validation is warranted.

Correspondence to: Edoardo Gaude, PhD, University of Cambridge, Li Ka Shing Centre, Robinson Way, Cambridge CB2 0RE, United Kingdom, Email edoardo.gaude@ pockitdx.co.uk; or Joshua D. Bernstock, MD, PhD, MPH, Department of Neurosurgery, Brigham and Women’s Hospital, 60 Fenwood Rd, Boston, MA 02115. Email jbernstock@bwh.harvard.edu *A. Ghosh and N.L.A. Nawabi contributed equally. †E. Gaude and J.D. Bernstock contributed equally. Supplemental Material is available at https://www.ahajournals.org/doi/suppl/10.1161/SVIN.125.002170. © 2026 The Authors. Stroke: Vascular and Interventional Neurology is published on behalf of the American Heart Association, Inc. and the Society for Vascular and Interventional Neurology by Wolters Kluwer Health, Inc. This is an open access article under the terms of the Creative Commons Attribution License, which permits use, distribution, and reproduction in any medium, provided that the original work is properly cited.

Reviewers Note: Although radiologic imaging remains the gold standard, by combining D-Dimer and GFAP (Glial Fibrillary Acidic Protein) into one combined test, with blood extracted by thin capillary tube, with a turn-around time of only 10 minutes, important triage decisions can be made in the field, enabling patients to reach the most appropriate Emergency Room depending on the type of stroke. Although prospective field validation is warranted, nevertheless this appears to be an important breakthrough in stroke management that may help avoid treatment delays if the information reported can be validated and utilized on a clinical basis.